From db591d1400d275e836a80dfaa2b2ef5b9b57bc64 Mon Sep 17 00:00:00 2001
From: John Lindgren <john@jlindgren.net>
Date: Sat, 21 Oct 2023 11:28:00 -0400
Subject: [PATCH] view: avoid raising same view over and over

Since view_move_to_front() now does more work than it used to
(updating XWayland server stacking order), try to avoid doing that
work unnecessarily.
---
 include/labwc.h        |  7 ++++++-
 src/view-impl-common.c |  9 ++++++---
 src/view.c             | 19 +++++++++++++++++++
 3 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/include/labwc.h b/include/labwc.h
index bae2dfb9..a870345e 100644
--- a/include/labwc.h
+++ b/include/labwc.h
@@ -238,12 +238,17 @@ struct server {
 	struct wlr_box grab_box;
 	uint32_t resize_edges;
 
-	/* SSD state */
 	/*
 	 * Currently focused view. Updated with each "focus change"
 	 * event. This view is drawn with "active" SSD coloring.
 	 */
 	struct view *focused_view;
+	/*
+	 * Most recently raised view. Used to avoid unnecessarily
+	 * raising the same view over and over.
+	 */
+	struct view *last_raised_view;
+
 	struct ssd_hover_state *ssd_hover_state;
 
 	/* Tree for all non-layer xdg/xwayland-shell surfaces */
diff --git a/src/view-impl-common.c b/src/view-impl-common.c
index f8bdb3ee..ede58bf1 100644
--- a/src/view-impl-common.c
+++ b/src/view-impl-common.c
@@ -55,9 +55,12 @@ view_impl_map(struct view *view)
 void
 view_impl_unmap(struct view *view)
 {
-	struct seat *seat = &view->server->seat;
-	if (seat->seat->keyboard_state.focused_surface == view->surface) {
-		desktop_focus_topmost_view(view->server);
+	struct server *server = view->server;
+	if (view == server->focused_view) {
+		desktop_focus_topmost_view(server);
+	}
+	if (view == server->last_raised_view) {
+		server->last_raised_view = NULL;
 	}
 }
 
diff --git a/src/view.c b/src/view.c
index 38cac17e..106a2aa7 100644
--- a/src/view.c
+++ b/src/view.c
@@ -1345,6 +1345,7 @@ move_to_front(struct view *view)
 	if (view->impl->move_to_front) {
 		view->impl->move_to_front(view);
 	}
+	view->server->last_raised_view = view;
 }
 
 static void
@@ -1353,6 +1354,9 @@ move_to_back(struct view *view)
 	if (view->impl->move_to_back) {
 		view->impl->move_to_back(view);
 	}
+	if (view == view->server->last_raised_view) {
+		view->server->last_raised_view = NULL;
+	}
 }
 
 /*
@@ -1365,6 +1369,17 @@ void
 view_move_to_front(struct view *view)
 {
 	assert(view);
+	/*
+	 * This function is called often, generally on every mouse
+	 * button press (more often for focus-follows-mouse). Avoid
+	 * unnecessarily raising the same view over and over, or
+	 * attempting to raise a root view above its own sub-view.
+	 */
+	struct view *last = view->server->last_raised_view;
+	if (view == last || (last && view == view_get_root(last))) {
+		return;
+	}
+
 	struct view *root = view_get_root(view);
 	assert(root);
 
@@ -1517,6 +1532,10 @@ view_destroy(struct view *view)
 		need_cursor_update = true;
 	}
 
+	if (server->last_raised_view == view) {
+		server->last_raised_view = NULL;
+	}
+
 	if (server->seat.pressed.view == view) {
 		seat_reset_pressed(&server->seat);
 	}
-- 
2.52.0